Sometimes you stumble across little gems, squirreled away in the back closets, like these illuminance meters, acquired in March of 1964. Sadly, no cost etched into the side. Eventually, these were replaced with more modern versions, before being phased out of labs entirely.
We can guess how they were used – being next to a box of slide frames with a rainbow of color filters – and assume they’re not making a comeback. But check out all of that tiny, mid-century text crammed on there!
- “Below normal for good visibility”
- “Satisfactory for book print and general work”
- “Suitable for ordinary reading such as newsprint”
- “Prolonged eye effort, requiring excellent visibility”
Especially intrigued at the specific note about newsprint requiring twice the incident light of other reading, writing, and general tasks.